BackgroundPheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors of the adrenal glands and paraganglia, occurring sporadically or as a range of hereditary tumor syndromes. About 30% of PPGLs are attributed to germline mutations. Clinical presentation, including localization, malignant potential, and age of onset, varies depending on the genetic background. Genetic testing for PPGLs is not well studied in Southeast Asia. We reviewed clinical management of PPGLs in Singapore, highlighting current gaps in clinical practice.MethodsMedical records of patients with PPGLs between 2005 and 2016 were reviewed. Diagnosis was confirmed histologically and stratified into sporadic or familial/syndromic (FS).ResultsTwenty‐seven (21.8%) patients were referred to the Cancer Genetics Service (CGS). FS PPGLs (18.5%) and extra‐adrenal PPGLs (58.1%) incidences were higher than previous studies. Referrals were lower for sporadic PPGLs compared to FS PPGLs (3.7% vs. 100%). Referrals were highest at diagnosis age <20 years old (80%) and decreased with increasing age; ≥20–<40 years old (32.1%), ≥40–<60 years old (10.6%). Genetic testing was taken up in 12/27 (44.4%) patients of which 7/12 (58.3%, 3 SDHB, 2 SDHD, 2 VHL) had germline mutations.ConclusionOpportunities for genetic testing are frequently missed due to low referral rates in patients with apparently sporadic PPGLs, particularly between ages 20‐60.

We describe a patient with adrenal phaeochromocytoma who presented with peripheral vasospasm and ischaemia and other manifestations mimicking features of systemic sclerosis, which resolved after resection of the tumor. Phaeochromocytoma should be suspected in patients with features of scleroderma who are negative for auto-antibodies.

Pheochromocytomas are thought to be uncommon in the elderly. However, the prevalence is likely to be higher than reported, as older patients are less likely to be diagnosed due to absence of classical symptoms of sympathetic overactivity and confounding effects of aging, comorbidities, and medications. We describe a hypertensive elderly patient with incidentally diagnosed pheochromocytoma complicated by recurrent urosepsis, cardiomyopathy, and fatal myocardial infarction. Our case demonstrates that, in older hypertensive patients without classical symptoms, orthostatic hypotension and urinary retention, which are common in the elderly, may indicate catecholamine excess and that the deleterious cardiovascular consequences of catecholamine excess in the elderly are not prevented by pharmacological α-and β-blockade.

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The management of diabetes mellitus in an insulin-dependent patient is challenging in the setting of concomitant antibody-mediated-insulin hypersensitivity. We report a case of a 62-year-old woman with pre-existing type 2 diabetes mellitus of 10 years duration who developed type 3 hypersensitivity reaction to insulin analogue detemir, and subsequently, severe diabetic ketoacidosis (DKA). She was C-peptide negative and was diagnosed with insulin-dependent diabetes. Despite increasing dose adjustments, insulin-meal matching, and compliance with insulin, she experienced episodes of unexpected hyperglycaemia and hypoglycaemia. The development of rash after detemir initiation and rapid progression to DKA suggests an aberrant immune response leading to the insulin allergy and antibody-induced interference with insulin analogues. Glycaemic control in the patient initially improved after being started on subcutaneous insulin infusion pump with reduced insulin requirements. However, after a year on pump therapy, localised insulin hypersensitivity reactions started, and glycaemic control gradually deteriorated.